With the development of wireless communication technologies, there has been an increase in consumer use of various multimedia signals, and an interest in fourth generation (4G) or higher generation (e.g. 5G) communication systems is rapidly increasing according to the need for rapid transmission of the various multimedia signals in mobile environments.
4G or 5G communication systems provide a higher transmission rate, a wider bandwidth, and a higher Peak to Average Power Ratio (PAPR) than other communication systems, for example, 3G or 2G, such as GSM communication systems, which may result in high power dissipation when a power amplifier is supplied with a fixed supply voltage.
Efficiency of a power amplifier drops rapidly as its output power is reduced and the power amplifier operates in a more linear region. Amplitude-modulated signals with a high PAPR, such as in a 4G LTE-A system, have a probability distribution weighted when it is far away from maximum output power, resulting in inefficient operation of the power amplifier at the time-averaging power level.